//2.
#include<stdio.h>
int main()
{
	int n = 2;
	float m = 1.0f;
	float sum = 1.0f;
	while(m >= 1.0e-5)
	{
		m = 1.0f/(n*(n+1));
		n++;
		sum += m;
	}
	printf("sum = %f\n",sum);
	return 0;
}
